Despite a $1 billion-plus projected deficit and continuing fiscal problems resulting from Hurricane Sandy, Gov. Cuomo will vow in his State of the State Address Wednesday not to raise taxes during his third year in office, The Post has learned.

Cuomo, in the penultimate year of his term with an extraordinary 70 percent-plus approval rating, will insist that the state continue on the course of balanced budgets and reduced expenditures that he has steered since taking office after years of seemingly unending tax hikes and excessive spending.

“The key to the governor’s fiscal success has been ending the years of taxes and gimmicks that got the state in its fiscal mess in the first place. The governor intends to keep that going,’’ said a source familiar with the planned address.

“Being able to say that middle-class taxes in New York are the lowest they have been in 58 years has resonated throughout the business world. The governor will use the State of the State to continue to send that message,” the source continued.

Cuomo, who was elected pledging to hold the line on both spending and taxes, did raise taxes by $2 billion on the wealthy at the end of his first year in office, but he insisted he did so only in the face of a national economic slump that produced lower than expected state revenues.

And despite the fact that those hikes were accompanied by a lowering of tax rates on many in the middle class, New York is still one of the highest-taxed states, with what many experts call the most hostile business climate in the nation.

Meanwhile, Cuomo won’t call for any increases in fees or other charges — often a back-door way of imposing new taxes — when he presents his proposed budget this month, although he’s not expected to make that commitment in the State of the State.

His reliance on existing revenue streams will be good news for taxpayers, but is virtually certainly to be denounced by public-employee unions and their “progressive’’ allies, who routinely demand more state spending.

Cuomo will deliver an upbeat address to members of the Legislature and invited guests that will take credit for a number of economic improvements, including two balanced budgets, fiscal restraint, pension reform and a local property-tax cap, sources familiar with his address said.

He’ll also renew calls for an increase in the state’s minimum wage, for publicly financed statewide elections and, in what is sure to be one of the most contentious issues of the 2013 legislative session, tougher gun-control laws and a ban on “assault weapons,’’ the definition of which remains unclear.

Gun-rights advocates say “assault weapons’’ could, under New York law, wind up including semiautomatic pistols legally owned by licensed handgun owners. A source close to Cuomo, however, said the governor is targeting only military-style rifles.

“We’re very concerned that the use of the phrase ‘assault weapons’ is an effort by the governor to go after licensed handguns that are owned by law abiding individuals,’’ said New York State Rifle & Pistol Association President Tom King.

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Senate Republican Leader Dean Skelos, who proposed a package of tough new laws over the weekend for firearms-related crimes, has been privately warned that hundreds of thousands of gun owners will turn against the GOP if his members join with Cuomo in an “assault weapons’’ ban.

“If the Senate Republicans sell out legitimate gun owners, the reaction will be far worse then it was when some of their members backed gay marriage: It’ll be the end for them,’’ predicted a prominent gun-rights lobbyist.

Other initiatives Gov. Cuomo is expected to announce in his State of the State Address on Wednesday:

* Abolishing LIPA, under investigation for its poor performance after Hurricane Sandy

* Increasing mental-health screening required as part of a gun-control package

* Specifics on post-Sandy rebuilding plans; state’s intention to take over more emergency-response functions

* A push to decriminalize possession of small amounts of marijuana during stop-and-frisk searches